1. Field
Apparatuses and methods consistent with exemplary embodiments relate to a method of controlling a compressor system and a compressor system using the same, and more particularly, to a method of controlling a compressor system for preventing an occurrence of a surge and a compressor system using the same.
2. Description of the Related Art
When a turbo compressor fails to produce a pressure greater than a pressure resistance of a turbo compressor system, reverse flows occur in the turbo compressor. The phenomenon is referred to as a surge. When a surge occurs, flow is reversed, and thus, the pressure and flux are minutely changed. These changes cause mechanical oscillations, thereby causing damages to bearings and impellers of the turbo compressor system. In other words, the surge is a phenomenon that deteriorates the performance and shorten the lifespan of compressor components. Therefore, providing surge protection is a core feature of controlling a turbo compressor.
In the related art, to prevent the occurrence of a surge in a compressor system, a surge control line is set on a performance chart of the compressor system and the compressor system is controlled according to the surge control line. Particularly, a method of controlling a compressor system using such surge control line is disclosed in Japanese Patent Laid-Open Publication No. 2007-212040 (Title of the Invention: Turbo Refrigerator and its Control Method, Applicant: Mitsubishi Heavy Industry Ltd). The Japanese Patent Laid-Open Publication No. 2007-212040 discloses a technique for setting a surge control line, which has about 10% margin from a surge line set on a performance chart, and controlling a compressor system by opening of an inlet vane and a hot gas bypass according to the surge control line.
Furthermore, Japanese Patent Laid-Open Publication No. 2005-226561 (Title of the Invention: Low Duty Compressor Control Method in LNG ship, Applicant: Kawasaki Shipbuilding Corp.) discloses a technique for setting a surge control zone instead of a surge control line and keeping an operation point out of the surge control zone for surge protection.